Abstract

The generation and guiding of spin waves from and by magnetic domain walls are demonstrated. The spin waves radiate from pinned and oscillating magnetic closure domain walls and propagate linearly along a narrow path formed by the surrounding 180° asymmetric Bloch domain walls. The propagating spin wave modes are directly visualized by time-resolved magneto-optical Kerr microscopy with picosecond temporal resolution. A linear relationship between excitation frequency, wavelength, and number of spin waves per domain exists. Independent of the field excitation frequency, a constant phase velocity of spin waves propagation is obtained. Spin wavescharacteristics can be tuned by varying the magnetic domain dynamics, allowing for variable spin wavecharacteristics with magnetic fieldcharacteristics and histories.

Funding through the German Research Council (DFG, MC9/10-1) is highly appreciated. Furthermore, J.M. thanks the DFG for support through their Heisenberg Programme (DFG, MC9/9-1, MC9/9-2). We thank A. Gerber, I. Mönch, and E. Quandt for help with the sample preparation.